Date of Award
5-2012
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Legacy Department
Materials Science and Engineering
Committee Chair/Advisor
Luo, Jian
Committee Member
Skaar , Eric
Committee Member
Kornev , Konstantin
Committee Member
He , Jian
Abstract
This thesis reports a series of fundamental investigations of grain boundary wetting, adsorption and structural (phases) transitions in doped Ni, Cu and Si with technological relevance to liquid metal embrittlement, liquid metal corrosion and device applications. First, intrinsically ductile metals are prone to catastrophic failure when exposed to certain liquid metals, but the atomic level mechanism for this effect is not fully understood. A nickel sample infused with bismuth atoms was characterized and a bilayer interfacial phase that is the underlying cause of embrittlement was observed. In a second related study, we showed that addition of minor impurities can significantly enhance the intergranular penetration of bismuth based liquids in polycrystalline nickel and copper, thereby increasing the liquid metal corrosion rates. Furthermore, we extended a concept that was initially proposed in the Rice-Wang model for grain boundary embrittlement to explain our observations of the impurity-enhanced intergranular penetration of liquid metals. Finally, a grain-boundary transition from a bilayer to an intrinsic is observed in the Si-Au system. This observation directly shows that a grain boundary can exhibit a first-order 'phase' transition, which often implies abrupt changes in properties.
Recommended Citation
Meshinchi asl, Kaveh, "GRAIN BOUNDARIES STRUCTURES AND WETTING IN DOPED SILICON, NICKEL AND COPPER" (2012). All Dissertations. 930.
https://open.clemson.edu/all_dissertations/930